Electronic tube



Ell A. -SCDKQLOV ELECTRONIC TUBE Jan. 26, E954 INVENTOR David A. Sokolovbij.

Filed NOV. 2]., 1951 Patented Jan. 26, 1954 ELECTRONIC TUBE David A.Sokolov, Lynn, Mass., assignor to Columbia Broadcasting System, Inc.,doing business under the name of Hytron Radio & Electronics Co., Salem,Mass., a corporation of New York Application November 21, 1951, SerialNo. 257,562

6 Claims.

This invention relates in general to electronic tubes and in particularto such tubes in high voltage applications.

It is the usual procedure where it is desired to introduce high voltageto an electronic tube to take advantage of the insulating properties ofthe glass envelope by making the high voltage connection at a point onthe envelope remote from other leads. Although this arrangement ishighly satisfactory from the standpoint of isolation of high voltage,there are instances where undesirable results are obtained. In most tubestructures, the practice is to run all leads through the base pins tomake contact with the socket. Wiring of the socket into circuit is ofcourse done beneath the chassis on which the tube is mounted. When ahigh voltage connection is made to a point on the glass envelope, itbecomes necessary to run a lead above the chassis to make thatconnection. In television receiver circuits, for example, high voltageleads of this type above the chassis are enclosed in a shieldedcompartment to avoid shook hazard to those adjusting or servicing thereceiver. Such practice then requires the dismantling of shieldcompartments even for the simple purpose of tube removal.

One device practiced in an eifort to avoid the use of shieldedcompartments is to place the `entire tube beneath the chassis, usuallyin a horizontal position for economy of space. This leads to furthercomplications, since many tubes must be properly oriented within narrowlimits if horizontal operation is to be successful. Too, the problems oftube removal and of heat dissipation militate against such an expedient.

It is, therefore, an object of the present invention to provide anelectronic tube wherein the high voltage connection is isolated fromother connections.

lt is another object of the present invention to provide an electronictube which may be conventionally mounted without exposed high voltageleads.

It is a further object of the present invention to provide an electronictube structure wherein an isolated lead is available beneath the chassison which the tube is mounted.

In general the present invention consists in an electronic tubestructure wherein a lead is brought through the exhaust tubulation, thetip, and the tube key. Provision is made for connecting circuit wiringto the lead by means of a cap and socket connector. For a betterunderstanding of the present invention together with other and furtherobjects, advantages and features. reference should be made to thefollowing detailed description which is to be readv in connection withthe annexed drawing, the single figure of which is a sectional view of apreferred embodiment of the invention.

Referring now to the drawing, there is illustrated an electronic tube IIhaving a glass envelope I3 and a base of the octal type I5. Base i5 iscemented to envelope I3 and has eight pins extending therefrom, pins I'Iand I9 being representative. Leads l22! and 23 extend from pins Il andI9 and, as is common in the electronic tube art, are sealed in stempress 29. Tubulation 3l communicates with the interior of envelope i3through an opening beneath stem press 29 and terminates in a tip 33.Lead 35 connects to electrode 3l, which in this instance is an electrodedesigned to be operated at high voltage. Lead 35 then passes intotubulation 3| and through its length. Tip 33 is actually formed overlead 35 n when envelope I3 has been sufficiently evacuated during themanufacture of electronic tube ii. Lead 35 then extends into key 39 andpasses through the end thereof. Cap Il! is cemented to the end of key 39and a soldered connection is formed between 4I and lead 35. It is, ofcourse, equally simple to embody the present invention in tubes using abutton rather than stem press 29, the high voltage lead 35 beingconnected in the same manner as outlined above and passing through thetubulation which communicates cen trally of the button with the interiorof the bulb.

It may be seen that lead 35 is substantially completely isolated fromall other leads of the tube, on both the evacuated and the unevacuatedsides. On the evacuated side, lead 35 passes through tubulation 3l andmay be spaced any reasonable amount from the other electrode leads asthey pass through the stem press. On the unevacuated side, the thicknessof the wall of the key in addition to the spacing between pins and keymaintain lead 35 entirely apart from the other leads of the tube.

Suitable connections can easily be made to the isolation lead below thechassis with no interference with conventional connections or socketwiring. Also, if desired, the socket may be modilied to receive cap IIIwith resilient contact members appropriately located for plug-inconnection.

While what has been disclosed is the preferred embodiment of theinvention, the structure need not be limited to the exact details shown,since the separate concepts of utilization of the tubulation forinsulation and high leakage resistance paths as well as the use of thetube key for similar purposes each are believed to be novel. Hence,

3 the invention should only be limited by the spirit and scope of theappended claims.

What is claimed is:

1. In combination with an electron tube, a lead connected to one of theelectrodes of said tube, said lead passing through the exhausttubulation of said tube, the tip on said exhaust tubulation being formedaround said lead, a base on said tube having a key, said lead alsopassing through said key, and means for connecting external circuitelements to said lead.

2. In combination with an electron tube, a lead connected to one of theelectrodes of said tube, said lead passing through the exhausttubulation of said tube, the tip on said exhaust tubulation being formedaround said lead, a base cemented to said tube and having a hollow key,said tip being disposed within said key, said key having an apertureformed therein, and a cap cemented to the end of said key, said leadpassing through said aperture in said key and being electricallyconnected to said cap.

3. An electron tube comprising, a glass en velope, a plurality ofelectrodes Within said envelope, a similar plurality of leads each beingconnected to one of said electrodes, a base cemented to said glassenvelope, said base having a central key and a number of pins extendingtherefrom, means for connecting each of said plurality of leads less oneto one of said pins through vacuum-tight seals, an exhaust tubeextending from said glass envelope and terminating in a vacuum-tight tipwithin said central key, said one of said plurality of leads extendingfrom one of said electrodes through said tip and through said key, and acap electrically con nected to said one lead and physically attached tothe extremity of said key.

Il. An electron tube comprising, a glass envelope, a plurality ofelectrodes within said envelope, one of said electrodes being designedfor high voltage operation, a similar plurality of leads, a base havinga central key and a number of pins extending therefrom, said base beingcemented to said envelope, a stem press enclosing said plurality ofleads less one, said plurality of leads less one each connecting one ofsaid electrodes to one of said pins through said stem press, an exhausttubulation having one end communicating with the interior of saidenvelope through an aperture formed adjacent said stem press, a tipbeing formed on the other end of said tubulation, said other end beingdisposed within said central key, and a hollow cap cemented to the endof said key, said key having an aperture formed therein communicatingwith the interior of said hollow cap, said one of said leads beingconnected from said cap to said one of said electrodes through said keyand said exhaust tubulation,

5. An electron tube comprising, an evacuated bulb, a base of insulatingmaterial cemented to said bulb, said base having a plurality of metallicpins circularly arranged and molded into the end thereof and a keycentrally disposed relative to said pins, a lead wire for connectingeach of the said pins to an element within said evacuated bulb, anadditional lead Wire passing through said key, and a connecting capattached to said key and electrically connected to said additional leadwire.

6. An electron tube comprising, an evacuated bulb, a plurality ofelectrodes within said bulb, one of said electrodes being adapted forhigh voltage operation, a lead wire connected to said one of saidelectrodes, means for insulating said lead wire, said means including anexhaust tubulation through which said lead wire runs, a base attached tosaid tube and having a hollow key portion through which said lead Wirealso passes, and means for making connection to said lead Wire disposedon the exterior of said hollow key portion.

DAVID A. SOKOLOV.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 902,032 Whitney Oct. 2'7, 1903 1,588,463 Houskeeper May 4,1926 2,509,709 Van Der Spek May 30, 1950 FOREIGN PATENTS lumber CountryDate 906,875 France June 4, 1945 OTHER REFERENCES Plion abstract 55,478,May l5, 1950 (vol. 634, p. 986, O. G. 5-16-50).

